Many vehicle vibrations typically become detectable to a driver at typical highway road speeds in excess of 25 mph. One exemplary cause of vehicle vibration at relatively high speeds corresponds to force variations at respective tire spindle locations which is typically referred to as tire high speed uniformity.
High speed uniformity (HSU) has become a growing concern in the automobile industry, and thus many tire manufacturers are being pressured to implement HSU control. Tire HSU measurement, however, has been difficult and quite costly, making HSU industrial control very difficult.
A multitude of various tire parameters have conventionally been identified and measured in an effort to predict and control these force variations and any resultant undesirable levels of vibration. It is desired to combine multiple tire parameter measurements to predict or determine tire high speed uniformity.
One known attempt at predicting tire HSU is disclosed in U.S. Pat. No. 5,396,438 (Oblizajek), which predicts HSU based on multiple low speed parameters such as radial run out (RRO), instantaneous rolling radius (IRR), and radial force variation (RFV) as obtained on low speed uniformity machines. Yet another example related to aspects of high speed uniformity is found in U.S. Pat. No. 6,065,331 (Fukasawa), which predicts higher order components of high speed uniformity based on low speed uniformity measurements. Low speed uniformity machines are well established and exist in all tire production lines. The above-referenced patents are incorporated herein by reference for all purposes. In light of these previous attempts to predict HSU parameters and the current marketplace focus on controlling HSU levels, it is desired to provide improved technology for characterizing tire HSU.
There are many contributing factors to tire HSU, and thus one of the biggest challenges in effectively controlling HSU lies in being able to properly identify such contributing factors in order to control corresponding levels of tire force variation and vehicle vibration. It has been determined in accordance with the present subject matter that mass uneven distribution generates a significant amount of high speed radial run out, which directly affects high speed uniformity. The previous attempts at predicting tire HSU parameters referenced above do not account for mass uneven distribution as a factor in predicting and controlling high speed uniformity. As such, it is desired in accordance with the presently disclosed technology to provide features for identifying mass uneven distribution at multiple harmonic levels.
Although known technology for characterizing tire high speed uniformity and affecting associated aspects of tire manufacturing have been respectively developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology.